1. Field of the Invention
The present invention relates to a device which measures the circumference of a tooth in order to properly fit an orthodontic band. More specifically, the measuring device has a loop which is placed around the tooth to be measured in order to determine its circumference.
2. The Prior Art
In the practice of orthodontics, there are two basic types of attachments, bands and brackets. A band is a thin strip of stainless steel which is placed around the circumference of a tooth and cemented in place. An orthodontic bracket is then welded to the band. The band is used solely to hold the orthodontic bracket onto the tooth. A bracket may also be bonded or glued directly to the surface of the tooth.
Bands are manufactured in various sizes with attachments already welded to the band. When the appropriate size band is chosen, it is then fitted and adapted to the individual morphology of that tooth. Previously, it was difficult to select the appropriate size band for a given tooth. The dentist would typically examine a tooth and simply guess at what size band would fit. If a band was the incorrect size, the orthodontist would select a larger or smaller band until he found the proper size. The bands which were tested but were the incorrect size would then have to be sterilized and resorted.
One appliance that has been used in the past for measuring the diameter of a tooth is the Dentometer manufactured by the Frol Corporation. This appliance is designed to measure anterior and some posterior teeth by placing the Dentometer perpendicular to the tooth surface and placing the measuring loop around the tooth. A measurement is then taken by using two fingers to rotate the take u knob which eliminates slack in the measuring loop. The take up knob is connected to a needle on a dial which will then indicate a number on a slip cover on the dial. Once the loop is snug around the tooth the operator will then read the dial and look up this number on the information guide to find the band size. When the Dentometer is used to measure posterior teeth, the cheek must be retracted in order to have access to the first and second molars. This makes it very difficult to measure posterior teeth, especially teeth which are farther back in the mouth, i.e., second molars are more difficult to measure than first molars. The Dentometer has not been recommended for use in measuring third molars.
The Dentometer is designed to measure teeth with the patient in a seated or a near vertical position. The Dentometer instructs the operator to hold the instrument with the palm facing down with the thumb and index finger pointing toward the mouth. The thumb and index finger are needed to adjust the knob, leaving three fingers to hold the appliance. Because the Dentometer has a needle with a removable slip cover, the angle at which the measurement is read can effect the accuracy of the reading.